A transmission may include a power take off (PTO) output to provide engine torque to devices that are external to a vehicle powertrain. An internal combustion engine may input torque to the transmission and the transmission may distribute the engine torque to vehicle wheels and/or the external device via the power take off output. In some examples, the external device may be included within the vehicle that incorporates the engine and the transmission. For example, the external device may be a hydraulic pump for supplying hydraulic oil to a cylinder that operates a compactor or a bed lift. Alternatively, the external device may be a log splitter or another device that is not part of the vehicle. In some examples, the external device may be provided by the vehicle manufacturer. Alternatively, the external device may be supplied by a vehicle system integrator.
In addition to a power take off, a vehicle may supply electrical power to operate one or more electrical loads such as, but not limited to, medical equipment, lights, and communications equipment. The electrical power may be supplied via an alternator that is driven by the engine. Nevertheless, if power consumed by the electrical loads is greater than alternator power output, current for operating the electrical loads may be provided by the vehicle battery. Consequently, charge may flow from the battery to the electrical load, thereby lowering battery charge more than is desired. One way to reduce the possibility of lowering battery charge is to provide a battery charge protection mode so that engine speed may be increased to increase alternator power output. However, adding a battery protection mode in a vehicle that includes a PTO may increase an actual total number of controller inputs and outputs to a number that is greater than a controller supports. Therefore, it would be desirable to provide PTO and battery charge protection within a single controller using few inputs and outputs while providing a desired level of functionality.
The inventors herein have recognized the above-mentioned issues and have developed a vehicle system, comprising: a controller including executable instructions stored in non-transitory memory to adjust speed of an engine in response to a signal level applied to an input of the controller, the input having a full scale range, the full scale range divided into a plurality of subranges, the plurality of subranges including a power take off subrange and a battery charge protection subrange.
By dividing a full scale range of an input of a controller into a plurality of subranges, it may be possible to provide the technical result of providing a power take off mode and a battery charge protection mode based on a level of a single signal at the controller input. Consequently, a single input may be the basis for commanding and operating the vehicle powertrain. In one example, an input range of a controller voltage or current input may be divided into a plurality of subranges. Each of the plurality of subranges provides different data than each of the other subranges of the voltage or current input. The vehicle powertrain may be operated based on the subrange the signal is within.
For example, a controller voltage input may have a full scale range from 0-5 volts. A first subrange may be provided for signals that are over 4.9 volts and that are applied to the controller voltage input. A second subrange may be provided for signals less than 4.9 volts and greater than 0.5 volts. A third subrange may be provided for signals less than 0.5 volts and greater than 0.3 volts. A fourth subrange may be provided for signals less than 0.3 volts and greater than 0.1 volts. A fifth subrange may be provided or signals less than 0.1 volts. Each of the five subranges correspond to a different powertrain operating mode.
The present description may provide several advantages. In particular, the approach may reduce a number of controller inputs used to provide a desired actual total number of powertrain operating modes. Further, the approach may provide subranges that reduce the possibility of inadvertently entering an undesired powertrain operating mode. Additionally, the approach may provide a simply way to interface between components provided by different manufacturers.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.